OK and the solar voltage is set to 55.2 and apparently causes no issue. But to make a point the charge continues to 55.66 to make sure there is some drama with the cell over volt.
Active balancer or not?
- Thread starter MullerEnergy-Australia
- Start date
Alkaline
Solar Wizard
active balancer is fine, it may take a little longer to top balance but for lazy people that don't want to bother balancing when assembling it is good.
Andy is just being too harsh looked like by the end of the video they all reached full anyway just leave it plugged I would say.
Andy is just being too harsh looked like by the end of the video they all reached full anyway just leave it plugged I would say.
Capt Bill
Sailing Options
I would like to see the any balancers test happen at high amperage IN, ... near the top voltage of the Charge cycle; ... because that is where I my LifEpo4 cells might get wonky in their balance. I seem my wonky cell balance even out just sitting there with little or no amp IN or OUT .. so in my mind, testing an active balancer without high amps in or out ... seems like a meaningless test; ... because I have seen unbalanced cell at highest charge even out after sitting 10mins by themselves with no IN or out currents. My Two Cents ;+)
Alkaline
Solar Wizard
Andy posted a follow up video, in it the JK actually did the worse, so basically NO balancing was the winner. I think it has more to do with how much amps or how hard you are hitting your battery. If its a very low discharge, probably the BMS balancer is all you need.
That Being said, I know from personally experience anytime I pushed my 8s pack hard e.g. pulling 2000+ watts the built in balancer did not do jack. These were with XUba cells back in 2019.
It wasn't until I added an active balancer that things started working properly. So cell quality has something to do with.
For me I just leave it on, I fully charge the battery like 2-3 times a year. The active balancer does it job in about 4 hours of so and brings them all up to 3.63.
I know for a fact the cells I got from xuba were grade B, but this was back when the OG Amy was with xuba and everyone was like Hell Ya Amy... haha....
That Being said, I know from personally experience anytime I pushed my 8s pack hard e.g. pulling 2000+ watts the built in balancer did not do jack. These were with XUba cells back in 2019.
It wasn't until I added an active balancer that things started working properly. So cell quality has something to do with.
For me I just leave it on, I fully charge the battery like 2-3 times a year. The active balancer does it job in about 4 hours of so and brings them all up to 3.63.
I know for a fact the cells I got from xuba were grade B, but this was back when the OG Amy was with xuba and everyone was like Hell Ya Amy... haha....
My experience with using an active balancer on my house UPS (no solar) isnt great. After 9 or 10 months my well top balanced cells in a 48v pack with new good quality cells were a mess and I had to re top balance cell by cell. I turned it off and the cells stayed in much better balance. I am switching to a JK BMS soon which seems to do a beter job and has more precise setting control. I dont think having balancing on all the time is a good idea at this point.
I posted this in another thread, but it may be useful to someone here too.
The Heltec 5a active balancer is used in my system with two grade B 271ah 8s 24 VDC Lifepo4 battery banks and it works well.
For 4s 12VDC Lifepo4:
https://www.amazon.com/Heltec-Equalizer-Balancer-Equalization-Capacitor/dp/B08CKPZ7PH
For 8s 24VDC:
https://www.amazon.com/Heltec-Equalizer-Balancer-Transfer-Capacitor/dp/B08D9D4NGW
There are (run) solder pads on the Heltec active balancer that can be used to turn the balancer on and off with a switch.
My system uses the relay on the Victron Energy BMV 712 battery shunt display wired to the run solder pads to switch on and off the Heltec active balancer.
At voltages above 27.3VDC the Heltec active balancer is switched on and balancing begins. As the voltage continues to increase above 27.3VDC the Solar Charge Controllers in the system are programmed to go into Boost (absorb) charge at 28 to 28.2VDC for 10 minutes. During boost charge mode the Heltec active balancer keeps all cell voltages at less than 3.55VDC as the cells balance. At the end of 10 minutes of boost charge mode all cells are within 30 mv or less. After 10 minutes of boost the SCC's are programmed to go into float mode at 27.4VDC. The cells continue to balance and after a few minutes in float the cells are within 15 mv or less. The SCC's stay in float mode while suppling loads during the day. Toward the end of the day (or if clouds build) when SCC's cannot hold float and the battery voltage goes below 27.2 the active balancer is turned off by the Victron shunt relay.
Originally the Heltec active balancer was just wired to the cells and it ran all the time, but I found that cells would balance mid charge and when the voltage approached the boost voltage at high current charge, some of the cells would trigger the BMS cell voltage limit (3.65 VDC) and shut down the battery bank. During mid charge of the battery banks some of the cells can vary 30mv or more and the Heltec balancer would balance the cells at mid voltage throwing off my top balance. I guess that's due to grade B poorly matched cells. Once the Heltec active balance was triggered to only balance at 27.3 VDC and above everything worked fine.
Due to the load demands on my off grid solar system it may be weeks before the system is able to charge up to Boost (absorb) charge level of 28 to 28.2VDC depending on sunny vs cloudy days in my area. Even with that amount of time in-between boost (full charge) the cells still balance well with the Heltec 5a active balancer. Without the Heltec active balancer one or more of the battery bank cell(s) was prone to over voltage triggering a BMS disconnect on that battery bank.
With my two Overkill Solar 8s BMS set at 3.65 Cell Voltage Limit this works well for both battery banks that are in parallel configuration.
It is my understanding that a Digital low voltage battery cut-off relay module is able to turn on and off the Heltec active balancer like the Victron shunt relay, but I have not tried it since my system has the Victron BMV 712 shunt. If some tries this battery cut-off relay module please post your results here.
https://www.amazon.com/NOYITO-Voltage-Detection-Protection-Discharge/dp/B07DS33JVJ
It would depend which type of active balancer you use.
The ones without capacitors are usually not 'active', but just dump the extra volts.
You can't trust the Chinese, they will say anything to sell their products.
I have bother (Heltec style and chip style), the chip style just doesn't work and gets hot.
The Heltec style works but not quickly, leave it for a week and all the cells are perfectly balanced.
I use an 8 cell Heltec balancer across the 8 worse cells (for high and low) in my 16 cell sh battery pack.
Without it one cell would always quickly reach high cutoff on charge, and a different cell would always quickly reach low voltage on discharge.
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Capt Bill
Sailing Options
Thanks for details. Yes to figuring out how to utilize active balancers at about >3.40cell volts ... and turned em off at <3.4v ... That makes lot of sense to me after my more recent studying. ... Here's the most recent voltage detection relay I just ordered to test out (another inexpensive option : https://www.ebay.com/itm/264578819502?var=564344104339
Alkaline
Solar Wizard
Well I think we need to summarize active balancer:
1) We all agree it is great for balancing your cells when you are charging to full.
2) Not so great when the battery pack is just being used normally, its almost as if you don't want the balancer to be turned on at all.
3) So hopefully they can release a new version of this that be a TOP active balancer designed for LIFEPO4 that will turn on at 3.4 volts only and stop at 3.65, this will mean no more balancing when the battery is being used.
That being said, here is the flip side:
1) Active balancer works good for people using heavy discharging, e.g. .5C or higher, here it can help take load off if you have a weak cell, the built in balancer will take forever when you have a true misbalancing because of the load.
2) If you built your battery and never bothered balancing, active balancer is a nice lazy person's approach to balancing
3) Active balancer takes load of your BMS balancing and potentially save your more expensive device.
So it depends on your situation, I think for people using in a stationary situation using it as backup power that will only see low charging/discharging rates, probably not worth it.
If you are in a RV/Trailer and are using it to run of a coffee pot, then yes I believe you will have more benefit that downsides form an active balancer.
I found the active balancer worked better for me, able to bring all cells to balance usually in 1 hour Using it on a 8s 24v home built battery with Luyuan 280K cells and LV2424 inverter I run a small 9.5 BTU a/c with it and have 800 watts of solar with a JBD 8s 100A BMS.
Running a few devices I have pulled about 80 amps form this setup which is enough to cause even the grade A cells to move around a bit I find my cell 6 hits HVC fastest. With the built in balancer it would balance and balance all the time even after a week cells would not get all to 3.6.
With the active within 1-2 hours they are fully balanced.
ALSO NOTE I found that I had to run my inverter to 29 VOLTS fully charged to get this to work, when I ran it at 28 volts it would take forever, looks like the little up voltage made all the difference.
1) We all agree it is great for balancing your cells when you are charging to full.
2) Not so great when the battery pack is just being used normally, its almost as if you don't want the balancer to be turned on at all.
3) So hopefully they can release a new version of this that be a TOP active balancer designed for LIFEPO4 that will turn on at 3.4 volts only and stop at 3.65, this will mean no more balancing when the battery is being used.
That being said, here is the flip side:
1) Active balancer works good for people using heavy discharging, e.g. .5C or higher, here it can help take load off if you have a weak cell, the built in balancer will take forever when you have a true misbalancing because of the load.
2) If you built your battery and never bothered balancing, active balancer is a nice lazy person's approach to balancing
3) Active balancer takes load of your BMS balancing and potentially save your more expensive device.
So it depends on your situation, I think for people using in a stationary situation using it as backup power that will only see low charging/discharging rates, probably not worth it.
If you are in a RV/Trailer and are using it to run of a coffee pot, then yes I believe you will have more benefit that downsides form an active balancer.
I found the active balancer worked better for me, able to bring all cells to balance usually in 1 hour Using it on a 8s 24v home built battery with Luyuan 280K cells and LV2424 inverter I run a small 9.5 BTU a/c with it and have 800 watts of solar with a JBD 8s 100A BMS.
Running a few devices I have pulled about 80 amps form this setup which is enough to cause even the grade A cells to move around a bit I find my cell 6 hits HVC fastest. With the built in balancer it would balance and balance all the time even after a week cells would not get all to 3.6.
With the active within 1-2 hours they are fully balanced.
ALSO NOTE I found that I had to run my inverter to 29 VOLTS fully charged to get this to work, when I ran it at 28 volts it would take forever, looks like the little up voltage made all the difference.
Capt Bill
Sailing Options
IMO: ... Seeing new versions of TOP active balancer at econ prices vs BMS prices ... designed for LIFEPO4 ... would be Great. IMO: I would be ok if the balancer worked above 3.65 cell volts, while definitely wanting my balancer to turn on only at > 3.4 volts, or have that as an adjustable option !!!. ... I currently have 2 Grade B EVE 8 x 280Ah sets I am using with 2 older T version of the Chargery BMS8Ts that just have passive balancers (w adjustable balance parameters). My LiFePO4 cells use to be able to take full charge to 29 volts with the Chargery BMS8Ts, but now a days, I have to set my Absorption Charge setting to 28.0 volts (floating at 27.2 volts) ... to keep one or more cells from peaking high enough to trigger BMS disconnect of charge in, or full battery. This is why I am studying active balancer options. I have the less expensive Heltec 5a active balancer to try out next; with plans to automate it's on and off switch option. I am also looking at the newer JK and Chargery BMS options that now have active balancers inside the BMS. Getting ready for my 3rd 24v 280Ah battery bank; ... I would like see my aged LifePO4s take a full charge up to 29 volts again without the peakers cells triggering BMS shut downs. I would then think my set up is dialed in, and would then likely dial my top charge voltage back down for longevity of battery cycles. I Am Learning More All the Time from my hands on experimenting; ... while appreciating these various forums on topic. Thanks for Summary :+)
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Alkaline
Solar Wizard
I message hankzor store on alibaba to see if they make a version that works on 3.4-3.65 ONLY let see what they say.
I think you can set the voltage on the JK BMS to start active balancing using the supercaps.
Daniel LS
New Member
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- Feb 9, 2021
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Did you got any answer?
I haven't look in detail about this device but Andy on The Offgrid Garage just posted a video where he found a relay to use with that balancer that turns on for the voltage ranges you want (of the entire pack, not individual cells).
Daniel LS
New Member
- Joined
- Feb 9, 2021
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Yes, seen it. It's an option, but would be better if the balancer itself started at a higher voltage.
It one more thing to put in the battery box, and I don't have much space there. Also a relay, so it will draw some mAh.
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